Parents do not generally treat their stepchildren less favorably than their own, going contrary to the so-called "Cinderella" Effect.
The latter states that it is biologically inevitable that parents care less for stepchildren because they do not spread their genes. However, researchers have discovered an important exception. If there is a reasonable chance of increasing wealth in the parents' environment then no difference is made between one's own children and stepchildren. Thus, parental care depends on more than just the biological relationship.
This is the result of a study published by Max Planck Institute for Demographic Research researcher Kai Willführ together with Alain Gagnon from the University of Montreal in the scientific journal "Biodemography and Social Biology." "We are now able to prove that the Cinderella effect is not an inevitable reflex of stepparents," says Kai Willführ. The scientists investigated if and how strongly parents neglected their stepchildren by looking at the mortality of children in historic patchwork families from the 17th to 19th century. They compared the Krummhörn region of East Frisia (Germany), which was a densely populated area with little space for demographic development, and the growing Canadian settlements in Québec. For both areas they calculated how the children's chances of survival changed when a stepmother moved in.
The extent of this effect is striking: if a Krummhörn girl lost her mother early, the likelihood of her dying before the age of 15 more than doubled compared to a girl whose mother did not die. If the father remarried and the stepmother joined the family, mortality doubled again. Thus, the arrival of a stepmother affected the girls in East Frisia as much as the death of their own mother. In Québec, however, the risk of dying young barely changed when the new mother moved in.
"The stepmothers in Québec seemed to understand that the offspring from their husband's first marriage were not competition for their own children with their new husband," says researcher Kai Willführ. "Families in Quebec during this time were comparatively huge," explained Professor Alain Gagnon. "French-Canadian families in the 17th to 19th centuries grew to fill the empty land, and more hands meant greater food security or even wealth. Children from a previous marriage could often help the step-parent care and educate their younger brothers and sisters." On the contrary, according to the "Cinderella effect", stepparents would always consider "foreign" children to be competitors to their own children and could thus neglect them.
Care for children is strategy But that only happened in Krummhörn, where siblings competed for basic needs. "We assume that stepmothers neglected, exploited or even abused the children from their husband's first marriage," says socio-biologist Willführ. The fact that this only happened in East Frisia shows that the context in which patchwork families are living - whether there is room for economic development or not - strongly influences how parents allocate their affection to their own children and stepchildren. "The difference is due to the scarcity of resources. It wouldn't be going too far to say that we could talk about a difference between the New World and the Old, between Europe and North America," demographer Gagnon said. "Our popular culture is constantly looking for Cinderella's Evil Stepmother, but cases such as reported in the movie "Little Aurore's Tragedy" here in Quebec were the exception rather than the rule." Although the scientists used historic data, their results have fundamentally challenged the veracity of the "Cinderella effect. "It is therefore also true today, that stepparents are not always evil," says researcher Kai Willführ.
For their study, Willführ and Gagnon traced thousands of children up to age 15 in East Frisia and Québec. By individually reconstructing whether and when a parent died, a stepmother or stepfather moved in, and whether half-siblings were born during this period, they were able to calculate the influence of all those events on the survival rate of boys and girls. Dates of births, christenings, weddings and funerals were taken from databases built from old church registers. For the Krummhörn region in East Frisia the researchers looked at the birth cohorts from 1720 to 1859, and for Québec at those born from marriages that took place from 1670 to 1750. "Québec is special in that we have incredibly rich genealogical and family data available to us, notably through the Registre de la population du Québec ancien, build by the Programme de recherche en démographie historique at the Université de Montréal, or the Balsac database at the Université de Chicoutimi. However, we have constructed our study so that researchers working on other regions of the world can compare their findings to ours," professor Alain Gagnon says. "Our study shows that the Cinderella phenomenon may be discovered only where vital resources and potential for population expansion are extremely very limited."